1. Importance of atrial surface area and refractory period in sustaining atrial fibrillation: Testing the critical mass hypothesis 
Anson M. Lee, MD, Abdulhameed Aziz, MD, Jacob Didesch, BS, Kal L. Clark, MD, Richard B. Schuessler, PhD, Ralph J. Damiano, MD 
The Journal of Thoracic and Cardiovascular Surgery 
Volume 146, Issue 3, Pages (September 2013)
DOI: /j.jtcvs
Copyright © 2013 The American Association for Thoracic Surgery Terms and Conditions

2. Figure 1
The lesion set used to subdivide the atrium. After ablation around the pulmonary veins as a starting point, the atria were divided into 2 sections with lines 1a and 1b, taking advantage of the natural conduction block of the aortic and mitral annuli. The right atrium was further divided with lines 1 and 2, such that the area paced (marked by an asterisk) was progressively smaller after each iteration. On the left subdivision, line 2 removed the area of the left atrial appendage, and a final line (3) subdivided the remaining tissue area around the pacing electrode. SVC, Superior vena cava; IVC, inferior vena cava.
The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /j.jtcvs )
Copyright © 2013 The American Association for Thoracic Surgery Terms and Conditions

3. Figure 2
Dose–response relationship of normalized effective refractory period (ERP) versus acetylcholine dose at peak effect. ERP was normalized to the ERP measured before the administration of acetylcholine. As the dose of acetylcholine increased, the measured ERP decreased (P = .015).
The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /j.jtcvs )
Copyright © 2013 The American Association for Thoracic Surgery Terms and Conditions

4. Figure 3
Time course of effective refractory period (ERP), normalized to initial value at time 0 before infusion of acetylcholine at 0.01 mg/Kg/min. After 5 minutes, the ERP decreased to a stable level. At time 20 minutes, the infusion was turned off, and ERP recovered to baseline level within 5 minutes.
The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /j.jtcvs )
Copyright © 2013 The American Association for Thoracic Surgery Terms and Conditions

5. Figure 4
The probability of sustained atrial fibrillation (AF) (y-axis) is plotted against effective refractory period (ERP) (x-axis) and surface area (z-axis). As area decreased (dark grey to white), the probability of sustained AF decreased. As ERP increased, the probability of sustained AF decreased.
The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /j.jtcvs )
Copyright © 2013 The American Association for Thoracic Surgery Terms and Conditions

6. Figure 5
The predictive model of the sustainability of atrial fibrillation (AF) is plotted. For each range of effective refractory period (ERP), the probability of sustained AF (y-axis) increased with increasing surface area (x-axis). A line is plotted for specific values of ERP. As ERP increases, the probability of sustained AF decreases. The area under the curve of the receiver operating characteristic curve is 0.878, and the McFadden rho2 was
The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /j.jtcvs )
Copyright © 2013 The American Association for Thoracic Surgery Terms and Conditions